A motor vehicle in a known way comprises a plurality of pieces of equipment performing various functions, notably controlled engine equipment such as, for example, the pump of the fuel injection system, the fuel injectors, the engine management system, etc.
These various pieces of equipment are connected, in the known way, via a wired vehicle communications network referred to as the CAN (Control Area Network) bus, to an electronic control unit of the vehicle known as the ECU.
This electronic control unit collects data relating to these various pieces of equipment in order to control or monitor these.
Nowadays, when a problem occurs with one of these pieces of equipment, the vehicle is taken to the repairer who performs a diagnosis by collecting and analyzing some of this data, known as public data, via a diagnostics device connected to the CAN bus.
When a piece of equipment is defective in a significant number of vehicles, for example several thousand vehicles, the manufacturer may recall said vehicles so as to change the affected equipment, this being expensive and time-consuming.
Furthermore, in a recall, it is not always possible to differentiate between components that are defective and those which are not since, for example, a processor may be fitted under the one same component reference but be supplied either by one supplier or by a competitor. If only the component supplied by only one of the suppliers is defective, it is not always possible to identify which processors are fitted with that component, and so all of the processors bearing that reference are then replaced. In that case, the manufacturer then systematically changes the potentially defective component, and this constitutes a significant disadvantage.
In addition, the time needed to detect a defect with a significant enough number of vehicles to trigger a recall may be relatively long, for example several months or years, and that delays modification of the defective equipment in production accordingly, and therefore constitutes a major disadvantage.
One known solution, described in document U.S. Pat. No. 8,370,020 B2, incorporated by reference herein, uses a Bluetooth® communication module to collect the public data available on the CAN bus of the vehicle and communicate them to a cell phone which transmits them to an Internet server. The server then analyzes the data in order to detect a problem with a piece of the vehicle equipment. This solution does not allow public data available on the CAN bus in limited quantity to be collected, and this constitutes a significant disadvantage. In addition, this solution allows only the vehicle comprising the defective equipment to be recalled, rather than a collection of similar vehicles, and this constitutes a major disadvantage.
Also known is document US 2008/255721 A1, incorporated by reference herein, the key objective of which is to collect anomaly data relating to a diagnostics code, identifying the groups of vehicles concerned, and to communicate wirelessly with a management center handling this data in order in particular for the management center to be informed of these detected anomalies. A dealer may use the diagnostics information recorded on the vehicle. That document is connected with detecting an anomaly using the engine control unit, more particularly the diagnostics unit the purpose of which is to flag up an anomaly or breakdown according to the legislation in force. That document is associated with the emission of a diagnostic signal of DTC (which stands for Diagnostic Trouble Code) type. According to the teachings of that document, the management center observes the confirmed faults communicated by the control unit on board the vehicle, and this for example makes it possible to log transient faults which are not held in memory in the vehicle diagnostics unit, and to inform the manufacturer or the dealers of these events. That document does not relate to a recall or selective recall method.